BILIARY EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY - SHORT-TERM AND LONG-TERM OBSERVATIONS IN AN ANIMAL-MODEL

The short- and long-term effects of biliary extracorporeal shockwave l ithotripsy (ESWL) using an electromagnetic lithotriptor were investiga ted in 26 pigs. After implantation of single human gallstones into the ir gallbladders, all but 4 control pigs were subjected to 4,000 or 8,0 00 shock waves and killed one day (n = 9), one week (n = 7), or one ye ar (n = 6) thereafter. Post-ESWL, no abnormalities of chest radiograph s or laboratory tests were detected. Apart from focal injury of the ga llbladder and liver, in 4 out of 9 pigs subpleural pulmonary hemorrhag es were found one day post-ESWL. However, tissue damage was largely re versed within one week and after one year only small hepatic scars per sisted as permanent damage. Stone fragmentation occurred in 19 (86%) o ut of 22 pigs, and was adequate (fragments less-than-or-equal-to 5 mm) in 9 (41%) pigs. Tissue damage and stone fragmentation after 4,000 as compared with 8,000 shock waves were not significantly different. The se data warrant further evaluation of this lithotriptor in human studi es.